1. Technical Field of the Invention
The present invention relates to a keyboard device for use in an electronic musical instrument.
In this specification and claims, a proximal portion of an electronic musical instrument and a keyboard device thereof to a performer is defined as a front portion, and a distal portion from the performer is defined as a rear portion.
2. Description of the Related Art
In a keyboard of an acoustic piano, a supporting part of a black key is disposed rearward from a supporting part of a white key. Because the black key is positioned slightly rearward from the white key, shifting the position of the support part of the black key rearward relative to the support part of the white key is advantageous. Namely, a ratio of distances from a key pressing point to the supporting part and from the supporting part to a driving point is made comparative between the white key and the black key, thereby decreasing a difference in touch feelings.
However, in the field of an electronic keyboard instrument, it is important to simplify the structure of the keyboard device. Thus, the key supporting part is commonly mounted without discriminating between the white key and the black key. One exemplary key supporting part is configured to include a recess member for receiving a protrusion provided at a rear end portion of each of the white and black keys to allow the keys to pivot (Patent Reference 1, Japanese Patent Laid-Open Publication No. H9-198036), and another exemplary key supporting part is configured to include an elastic piece which is integrally mounted to the rear end portions of the white and black keys to connect the keys and which is fixed to a keyboard frame (Patent Reference 2, Japanese Utility Model Laid-Open Publication No. H3-100894). The above-structured electronic keyboard instrument has the problems that a difference in touch feelings between the white key and the black key is increased and it is difficult for a performer to perform accurately or express delicately.